Online fundraising site Kickstarter says hackers got some of its customer data.

Kickstarter co-founder Yancey Strickler said in a blog post that hackers accessed usernames, email addresses, phone numbers and passwords. The passwords are encrypted, but the company said it's possible for a hacker to guess a weak or obvious password. It recommended that users change their passwords.

Hackers did not get credit card information, said New York-based Kickstarter, but two accounts saw unauthorized activity.